An essential part of the Koralmbahn line, the Granitztal tunnel chain with a length of about 6.1 km runs between the Lavanttal and the Jauntal valleys and crosses the Deutsch Grutschen, the Granitztal and the Langer Berg. In early 2016, Austrian Railways ÖBB made a decision for the Granitztal tunnel chain project, which was then already under construction, to test the 3D model‐based Building Information Modelling (BIM) design method in addition to conventional 2D design. One essential precondition for the application of the BIM method on transport infrastructure projects was recognised as the required data structures. In addition to the definition of general project requirements and standards for BIM, work started on the structuring and classification of the construction elements required for the tunnel structure and their properties. Of equal importance are the spatial positioning and location of the construction elements and the definition of topological relationships to each other. The article gives an insight into the current state of development of BIM data structures for tunnel structure and track superstructure at the ÖBB and is intended to make a contribution to initiating the development of such data structures by all the disciplines involved in tunneling and transport infrastructure. The prime intention is to provide the BIM data structures produced in this way as an active contribution to the further development of the open BIM standard IFC (Industry Foundation Classes) in the IFC Underground Construction Group at buildingSMART